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United States Patent |
5,508,577
|
Shiga
,   et al.
|
April 16, 1996
|
Electric rotating machine
Abstract
The provision of an electric rotating machine which can reduce the
mechanical and thermal loads applied thereto. Coil arms and coil trunks
are provided in roughly parallel orientation to the end faces of an
armature core only through insulating rings and insulating spacers. Metal
brush is disposed on coil arms, whereby the overall length of the armature
can be remarkably shortened. In addition, a commutator, conventionally
necessary, can be eliminated, whereby the length of the production process
for the armature can be reduced. Moreover, in an arrangement where
projections of the upper coil arm are fit in holes of the insulating
spacer, as the displacement of the upper coil arm towards the outer
periphery is regulated, the length of the axial protrusions of the upper
coil arm from the end face of the armature core can be minimized. In
addition, as extension portions and of the coil trunks are strongly
pressed against and fixed to the side of armature core by fixing members,
the resistance to the centrifugal force can be remarkably improved.
Furthermore, as the extension portion of the lower coil arm is fit in a
recessed part of the insulating spacer, the displacement of the lower coil
arm in the axial direction towards the outer periphery can be prevented.
Accordingly, the electric rotating machine according to the present
invention can withstand more than two times as high a rotational speed as
that of the conventional structure.
Inventors:
|
Shiga; Tsutomu (Nukata, JP);
Hayashi; Nobuyuki (Nagoya, JP);
Ohmi; Masanori (Anjo, JP);
Niimi; Masami (Handa, JP);
Murata; Mitsuhiro (Anjo, JP)
|
Assignee:
|
Nippondenso Co., Ltd. (Kariya, JP)
|
Appl. No.:
|
323346 |
Filed:
|
October 14, 1994 |
Foreign Application Priority Data
| Oct 15, 1993[JP] | 5-258717 |
| Oct 15, 1993[JP] | 5-258720 |
| Oct 15, 1993[JP] | 5-258731 |
| Nov 15, 1993[JP] | 5-284766 |
| Dec 21, 1993[JP] | 5-322810 |
| Dec 22, 1993[JP] | 5-323877 |
| May 31, 1994[JP] | 6-117993 |
| Sep 14, 1994[JP] | 6-219717 |
Current U.S. Class: |
310/201; 310/45; 310/91; 310/237; 310/248; 310/262 |
Intern'l Class: |
H02K 003/04 |
Field of Search: |
310/198,184,261,262,200,201,206,208,233,91,45,248,42
|
References Cited
U.S. Patent Documents
3209187 | Sep., 1965 | Angele | 310/266.
|
4591750 | May., 1986 | Major et al.
| |
4833769 | May., 1989 | Tomite et al.
| |
5130596 | Jul., 1992 | Umeki | 310/234.
|
5443553 | Aug., 1995 | Shiga et al. | 74/7.
|
Foreign Patent Documents |
288328 | Oct., 1988 | EP.
| |
387666 | Sep., 1990 | EP.
| |
2534085 | Apr., 1984 | FR.
| |
2127556 | Dec., 1972 | DE.
| |
3813317 | Nov., 1988 | DE.
| |
50-100505 | Aug., 1975 | JP.
| |
194541 | Aug., 1988 | JP.
| |
1-218341 | Aug., 1989 | JP.
| |
Primary Examiner: Skudy; R.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Claims
What is claimed is:
1. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
first lower coil arms electrically connected at one end part thereof to one
end part of said lower coil trunks and disposed substantially
perpendicularly to said shaft, said first lower coil arms extending
towards said shaft;
first upper coil arms electrically connected at one end part thereof to one
end part of said upper coil trunks and disposed substantially
perpendicularly to said shaft, said first upper coil arms extending
towards said shaft and connected at a second end part thereof to a second
end part of said first lower coil arms, adjacent said shaft;
brush means disposed to contact axially facing outer surfaces of said first
upper coil arms;
a first electrical insulator disposed between and in contact with said
first lower coil arms and one axial side surface of said armature core;
and
a second electrical insulator disposed between and in contact with said
first lower coil arms and said first upper coil arms.
2. The electric rotating machine according to claim 1, further comprising:
second lower coil arms electrically connected at one end part thereof to a
second end part of said lower coil trunks and disposed to extend
substantially perpendicularly to said shaft;
second upper coil arms electrically connected at one end part thereof to a
second end part of said upper coil trunks and disposed to extend
substantially perpendicularly to said shaft, said second upper coil arms
being connected at a second end part thereof to a second end part of said
second lower coil arms;
a third electrical insulator disposed between and in contact with said
second lower coil arms and a second side surface of said armature core;
and
a fourth electrical insulator disposed between and in contact with said
second lower coil arms and said second upper coil arms,
wherein said brush means includes a plurality of brushes contacting only
said axial outer surfaces of said first upper coil arms.
3. The electric rotating machine according to claim 1, wherein said
armature core is made of a plurality of metal plates contacting said
shaft, and said first upper coil arms and said second electrical insulator
have respective positioning means for engagement therebetween.
4. The electric rotating machine according to claim 2, wherein said first
and second lower coil arms and said lower coil trunks are integrally
formed, and said first and second upper coil arms and said upper coil
trunks are integrally formed, respectively, and wherein said shaft extends
through and is in contact with said armature core.
5. The electric rotating machine according to claim 1, wherein said first
lower coil arms have axially protruding portions extending along said
shaft at radially inner end parts thereof to electrically connect said
first lower coil arms to radially inner end parts of said first upper coil
arms, respectively.
6. The electric rotating machine according to claim 1 wherein a
circumferential width of said first upper coil arms on which said brush
means is disposed are circumferentially widened in radial direction
towards an outer periphery of said armature core.
7. The electric rotating machine according to claim 6, wherein clearance
grooves are formed by adjacent two said first upper coil arms, said
clearance grooves being formed in a one of a substantially spiral and a
radial shape extending in a direction opposite to a rotational direction
of said armature core from a radially inner periphery to a radially outer
periphery for providing an air flow path.
8. The electric rotating machine according to claim 1, wherein at least one
of said upper coil trunks and said first upper coil arms are made of a
good conductor with a Vickers hardness of at least about 55.
9. The electric rotating machine according to claim 1, wherein said first
upper coil arms are formed in a flat shape by press machining.
10. The electric rotating machine according to claim 1, wherein said first
upper coil arms are press machined and shear droop sides of said first
upper coil arms are used as the sliding surfaces for said brush means.
11. The electric rotating machine according to claim 1, further comprising
a metal holding plate disposed in the vicinity of said first upper coil
arms and rotatably holding said shaft, said holding plate holding said
brush means.
12. The electric rotating machine according to claim 1, wherein said first
upper coil arms extend radially outwardly in a direction opposite to a
rotation direction of said armature core, and wherein adjacent two of said
first upper coil arms form a groove therebetween for a radial airflow
path.
13. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms;
said lower coil arms having axially protruding portions extending along
said shaft at radially inner end parts thereof to electrically connect
said lower coil arms to radially inner end parts of said upper coil arms,
respectively; and
collar means pressing said upper coil arms against a side of an axial end
face of said armature core to prevent radial displacement of said upper
coil arms towards an outer periphery of said armature core.
14. The electric rotating machine according to claim 13, wherein at least
one of said upper and lower coil trunks and said upper and lower coil arms
are made by processing at least one of a sheet material and a wire
material.
15. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms;
a metal brush means disposed on said upper coil arms;
a circumferential width of said upper coil arms on which said brush means
is disposed being circumferentially widened in radial direction towards an
outer periphery of said armature core;
clearance grooves being formed by adjacent two said upper coil arms, said
clearance grooves being formed in a one of a substantially spiral and a
substantially radial shape extending in a direction opposite to a
rotational direction of said armature core from a radially inner periphery
to a radially outer periphery for providing an air flow path;
a depth of said clearance grooves roughly matching a thickness of said
upper coil arms.
16. The electric rotating machine according to claim 15, further comprising
an insulator disposed between said lower coil arms and said upper coil
arms provided with positioning parts for regulating circumferential and
radial relative displacement between said upper coil arms and said lower
coil arms.
17. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms;
insulators disposed between said lower coil arms and said armature core and
between said upper coil arms and said lower coil arms, respectively;
said insulator disposed between said lower coil arms and said upper coil
arms being provided with positioning parts for regulating circumferential
and radial relative displacement between upper coil arms and said lower
coil arms, said positioning parts comprising holes provided in said
insulator for receiving therein protrusion portions formed on said upper
coil arms.
18. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms;
insulators disposed between said lower coil arms and said armature core and
between said upper coil arms and said lower coil arms, respectively;
said lower coil arms having axial protrusion parts extending towards radial
end parts thereof, and wherein radially inner end parts of said insulators
are inserted between said axial protrusion parts and are circumferentially
adjacent to each other and have axially inner recessed parts recessed for
positioning.
19. An electric rotating machine comprising:
an armature core including slots:
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
first lower coil arms and second lower coil arms extending from first ends
and second ends of said lower coil trunks, respectively, substantially
perpendicularly towards said shaft, each of said first lower coil arms,
said second lower coil arms and said lower coil trunks being formed
integrally from a single coil;
first upper coil arms and second upper coil arms extending from first ends
and second ends of said upper coil trunks, respectively, substantially
perpendicularly towards said shaft, each of said first upper coil arms,
said second upper coil arms and said upper coil trunks being formed
integrally from a single coil; and
brushes disposed on said first upper coil arms,
wherein radial inner ends of said first upper coil arms and said second
upper coil arms are electrically connected to radial inner ends of said
first lower coil arms and said second lower coil arms, respectively,
adjacent said shaft.
20. An electric rotating machine according to claim 19, wherein said radial
inner ends of said first upper coil arms, said second upper coil arms,
said first lower coil arms and said second lower coil arms have respective
extensions extending axially along said shaft and electrically connected
thereat.
21. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms; and
collars pressing said upper coil arms against a side of an axial end face
of said armature core to prevent radial displacement of said upper coil
arms towards an outer periphery of said armature core.
22. The electric rotating machine according to claim 21, wherein said lower
coil arms have axially protruding portions extending along said shaft at
radially inner end parts thereof to electrically connect said lower coil
arms to radially inner end parts of said upper coil arms, respectively.
23. The electric rotating machine according to claim 22 wherein each of
said collars has a fixing portion fixed to said shaft, a ring portion
surrounding a radial outer surface of said axially protruding portion, and
a connecting portion connecting said fixing portion and said ring portion.
24. An electric rotating machine comprising:
an armature core including slots;
a shaft rotatably supporting said armature core;
upper coil trunks and lower coil trunks housed within said slots of said
armature core;
lower coil arms electrically connected at one end part thereof to one end
part of said lower coil trunks and disposed substantially perpendicularly
to said shaft, said lower coil arms extending towards said shaft;
upper coil arms electrically connected at one end part thereof to one end
part of said upper coil trunks and disposed substantially perpendicularly
to said shaft, said upper coil arms extending towards said shaft and
connected at a second end part thereof to a second end part of said lower
coil arms;
insulators disposed between said lower coil arms and said armature core and
between said upper coil arms and said lower coil arms, respectively;
said insulator disposed between said lower coil arms and said coil arms
being provided with positioning parts for regulating circumferential and
radial relative displacement between upper coil arms and said lower coil
arms, said positioning parts comprising one of holes and protrusion
portions provided on said insulator and said upper coil arms has one of
protrusion portions and holes provided thereon for engagement with said
positioning parts of said insulator.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims priority from Japanese Patent
Application No. 5-258717 filed Oct. 15, 1993; Japanese Patent Application
No. 5-258720 filed Oct. 15, 1993; Japanese Patent Application No. 5-258731
filed Oct. 15, 1993; Japanese Patent Application No. 5-284766 filed Nov.
15, 1993; Japanese Patent Application No. 5-322810 filed Dec. 21, 1993;
Japanese Patent Application No. 5-323877 filed Dec. 22, 1993; Japanese
Patent Application No. 6-117993 filed May 31, 1994; and Japanese Patent
Application No. 6-219717 filed Sep. 13, 1994, with the contents of each
document being incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an electric rotating machine.
More particularly, the present invention relates to an electric rotating
machine such as a starter motor for vehicles that can suitably be used as
an electric motor for high-speed rotations.
2. Related Art
Japanese Unexamined Patent Publication No. 2-241346, which corresponds to
U.S. Pat. No. 5,130,596, discloses an electric rotating machine having
upper and lower armature coils held within slots of an armature core. The
coils are extended in the axial direction to be cylindrical, with the
outer periphery of the upper coil being smaller in diameter than the outer
periphery of the armature core. The metal brush contacts the outer
periphery of the cylindrical surface. In this arrangement, the upper and
lower armature coils are fed with electric current through the metal
brush.
However, such an electric motor, particularly when used for high-speed
rotation, has the problem that high-speed rotation is disabled by heavy
mechanical loads caused by burdens on the molded resin cylinder, which
holds the coils composing the contact face for the metal brush. The
burdens on the molded resin cylinder are due to the centrifugal force
developed on the commutator face of the coil, heavy thermal loads caused
by the effect of the resisting heat generated on the commutator face, and
the frictional heat generated on the metal brush in high-speed rotations.
SUMMARY OF THE INVENTION
In view of the above problem, the present invention has as its primary
object the provision of an electric rotating machine that can reduce
mechanical and thermal loads.
It is a further object of the present invention to provide an electric
rotating machine which is suited for downsizing.
It is a still further object of the present invention to provide an
electric rotating machine which is suited for simplification of
manufacturing processes.
The electric rotating machine according to the present invention is
basically constructed as follows. The electric rotating machine includes
an armature core including slots, a shaft rotatably supporting the
armature core, upper coil trunks and lower coil trunks housed within the
slots of the armature core, lower coil arms electrically connected at one
end parts of the lower coil trunks, respectively disposed roughly
perpendicular to the shaft and extending in the direction of the shaft,
and upper coil arms electrically connected at one end parts to the upper
coil trunks, respectively disposed roughly perpendicular to the shaft and
extending in the direction of the shaft, and connected at the other end
parts to the other end parts of the lower coil arms respectively.
In the electric rotating machine according to the present invention, the
lower and upper coil arms of the upper and lower armature coils are
disposed roughly perpendicular to the shaft, and the upper coil arms are
connected to the other end parts of the lower coil arms. In this
arrangement, the lower and upper coil arms can be housed within a small
clearance protruding from the armature core, and the resistance to the
centrifugal force can be increased. Therefore, the mechanical loads can be
substantially reduced, and the lower and upper coil arms can be disposed
in the vicinity of the armature core. As a result, the heat generated at
the lower and upper coil arms can easily be dissipated to the side of the
armature core, whereby the thermal loads can also be reduced.
Further, according to the present invention, upper coil arms has a unique
shape and arrangement for functioning as a commutator, for providing
grooves which enhance air flow therethrough, and/or for providing good
dissipation of heat generated by metal brush.
Still further, according to the present invention, upper coil arms and
lower coil arms have unique shape and arrangement with armature core and
shaft for keeping fixed relation with armature core and shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and characteristics of the present invention, as
well as the functions of the related parts, will be appreciated from the
following detailed description, appended claims, and the drawings, all of
which from a part of this application. In the drawings:
FIG. 1 is an axial crossesectional view illustrating an electric rotating
machine according to a first embodiment of the present invention;
FIG. 2 is an axial cross-sectional view illustrating a rotor of the
electric rotating machine of the first embodiment;
FIG. 3 is a plan view illustrating an armature core of the electric
rotating machine of the first embodiment;
FIG. 4 is a plan view, partly in cross section, illustrating a part of an
armature coil of the electric rotating machine of the first embodiment;
FIG. 5 is a plan view illustrating a coil arm of the electric rotating
machine of the first embodiment;
FIG. 6 is a perspective outline view illustrating the layout of upper and
lower coil trunks of the electric rotating machine of the first
embodiment;
FIG. 7 is a cross-sectional view illustrating the upper and lower coil
trunks housed within the slots;
FIG. 8 is a plan view illustrating the armature of the first embodiment;
FIG. 9 is a plan view illustrating an insulating spacer of the first
embodiment;
FIG. 10 is a cross-sectional view illustrating a fixing member of the first
embodiment;
FIG. 11 is a cross-sectional view illustrating an insulating cap of the
first embodiment;
FIG. 12 is a typical view illustrating winding of the armature coil of the
first embodiment;
FIG. 13 is a perspective view illustrating another type of the armature
coil;
FIG. 14 is a perspective view illustrating still another type of the
armature coil;
FIG. 15 is a perspective view illustrating still another type of the
armature coil;
FIGS. 16A through 16C are perspective views illustrating the production
procedure for the armature coil;
FIGS. 17A through 17D are perspective views illustrating the production
procedure for another armature coil;
FIG. 18 is a cross-sectional view illustrating the positional relation
between the upper coil arm and the metal brush;
FIG. 19 is a cross-sectional view illustrating another connecting method
for the upper and lower coil arms;
FIG. 20 is a cross-sectional view illustrating still another connecting
method for the upper and lower coil arms;
FIG. 21 is a cross-sectional view illustrating still another connecting
method for the upper and lower coil arms;
FIG. 22 is an axial cross-sectional view illustrating the rotor of the
electric rotating machine according to a second embodiment of the present
invention;
FIG. 23 is an axial cross-sectional view illustrating the rotor of the
electric rotating machine according to a third embodiment of the present
invention;
FIG. 24 is an axial cross-sectional view illustrating the rotor of the
electric rotating machine according to a fourth embodiment of the present
invention;
FIG. 25 is an axial cross-sectional view illustrating the rotor of the
electric rotating machine according to a fifth embodiment of the present
invention;
FIG. 26 is an axial cross-sectional view illustrating the rotor of the
electric rotating machine according to a sixth embodiment of the present
invention;
FIG. 27 is an axial cross-sectional view illustrating a seventh embodiment
of this invention;
FIG. 28A is an enlarged plan view of a part of the seventh embodiment; and
FIG. 28B is a side view of the axial side end of the armature coil on the
commutator side of seventh embodiment in FIG. 27;
FIG. 29 is a partial wiring diagram of an inner conductor and an outer
conductor shown in FIG. 27;
FIG. 30 is an enlarged axial cross-sectional view of the seventh embodiment
shown in FIG. 27;
FIG. 31A through 31C shows an eighth embodiment in which FIG. 31A is an
axial cross-sectional view illustrating the state before an armature coil
holding portions and are welded. FIG. 31B is an axial front view, and FIG.
31C is a main enlarged plan view illustrating shape of protrusion portion;
FIG. 32A is an axial-cross sectional view illustrating the state after the
armature coil holding portions and are welded in the eighth embodiment,
FIG. 32B is an axial front view of the same, and FIG. 32C is an enlarged
plan view illustrating the protrusion portion; and
FIG. 33 is a partial enlarged axial cross-sectional view illustrating the
fixed state of the collar.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENTS
The first embodiment of the electric rotating machine according to the
present invention will be described with reference to FIGS. 1 through 11.
As illustrated in FIGS. 1 and 2, electric rotating machine 500 includes
shaft 510, an armature including armature core 520 rotatably and
integrally fixed on shaft 510 and armature coil 530, and fixed magnetic
poles 550 for rotating the armature. Fixed magnetic poles 550 are fixed on
the inner periphery of yoke 501.
Shaft 510 is rotatably held by metal bearing 906 provided in a supporting
member (not illustrated) and a metal bearing 905 fixed on the inner
periphery of end frame 900. At the front end of shaft 510 is formed gear
511 engaging with a gear of planetary gear mechanism (not illustrated).
Armature core 520 is formed by stacking a multiplicity of ring-shaped core
plates 521 illustrated in FIGS. 2 and 3, and shaft 510 is force or press
fit in a hole 522 made in the center of plates 521. Each core plate 521 is
punched out of a thin steel plate on a press, and insulated on the
surface. On the inside diameter side of core plate 521 (around the hole
522) are formed a plurality of punched holes 523, which reduce the weight
of core plate 521. On the outer periphery of core plate 521, a plurality
of axially extending (e.g., 25) slots 524 are formed to house armature
coil 530. On the outer periphery of core plate 521 and between the
respective slots 524 adjacent to each other are formed set claws 525 for
holding armature coil 530 housed within slot 524 in position. The claws
525 will be described in more detail later.
Armature coil 530 in this embodiment adopts a double-layer coil which
comprises a plurality of (e.g., 25) upper coil bars 531 composing an upper
armature coil and the same number of lower coil bars 532 composing a lower
armature coil, wherein upper coil bar 531 and lower coil bar 532 are
mutually stacked in the radial direction. Each upper coil bar 531 is
combined with each lower coil bar 532 and each end part of each upper coil
bar 531 is electrically connected to the end part of each lower coil bar
532 to form a loop coil.
Upper coil 531 made of a highly conductive metal (e.g., copper) extends
parallel to fixed magnetic pole 550. Upper coil bar 531 includes upper
coil trunk 533 held within slot 524 and a pair of upper coil arms 534
extending from the respective ends of the upper coil trunk 533 turning
innards therefrom to be perpendicular to the axial direction of shaft 510
and roughly parallel to both axial side faces 522 of the armature core
520. Here, both ends of the upper coil trunk 533 are joined to recessed
parts 534a (FIG. 6) formed at one end of the respective pair of upper coil
arms 534.
Upper coil trunk 533 is a linear bar with rectangular cross section as
illustrated in FIGS. 4 through 7. The periphery of upper coil trunk 533 is
covered with upper insulating film 540 (e.g., a thin resin film, such as
nylon, or paper). Upper coil trunk 533 covered with the upper insulating
film 540 is firmly held within slot 524 together with a lower coil trunk
536 (described later) as illustrated in FIG. 7.
As illustrated in FIG. 6, one of the pair of upper coil arms 534 is
inclined to the forward side in the rotating direction of armature, and
the other upper coil arm 534 is inclined to the backward side in the
rotating direction. The pair of upper coil arms 534 are inclined to the
radial direction at the same angle to upper coil trunk 533 and formed in
the same shape. Accordingly, even if upper coil arms 534 are horizontally
turned 180.degree. around the center of upper coil bar 531, upper coil bar
531 takes the same shape as if upper coil arms 534 were not turned. That
is, as there is no difference in shape between the pair of upper coil arms
534, the assembly process of assembling upper coil bars 531 to armature
coil 520 has a high efficiency.
Of the pair of upper coil arms 534, one located at the side of the end
frame 900 directly contacts, as commutator, the metal brush 910 (described
later) to electrically energize the armature coil 530. For this purpose,
at least the surfaces of upper coil arms 534 in contact with brush 910 are
smooth. The electric rotating machine of this embodiment does not require
any separate commutator for electrically energizing armature coil 530. As
a result, as there is no need to provide any separate commutator, the
number of necessary components can be reduced. In addition, as there is no
need to provide any separate commutator within yoke 501, the structure of
the electric rotating machine can be downsized in the axial direction.
Moreover, as upper coil arm 534 directly contacts the metal brush 910, the
heat generated by the sliding contact between upper coil arm 534 and metal
brush 910 is transmitted from upper coil arm 534 to upper coil trunk 533,
armature core 520, shaft 510, etc. As armature coil 530, armature core
520, shaft 510, etc. are considerably larger in heat capacity compared
with conventional separately provided commutators, the sliding contact
portion between upper coil arm 534 and metal brush 910 can be maintained
at a low temperature.
As illustrated in FIG. 8, each upper coil arm 534 gradually expands in the
radial direction towards the distal end, and the peripheral clearance
between mutually adjacent upper coil arms 534 is almost uniform from the
inner periphery thereof to the outer periphery thereof. This arrangement
substantially enlarges the contact area between metal brush 910 and upper
coil arm 534. As a result, the heat of metal brush 910 is easily
transmitted to the coil bars 531, whereby the temperature of metal brush
910 can be maintained at a substantially low level. It is to be noted that
FIG. 8 is depicted to illustrate the shape of the upper coil arm 534 for
easy understanding, and the number of the upper coil arms 534 does not
match with the number of the slots 524 illustrated in FIG. 3.
Furthermore, the clearance groove (space groove) between mutually adjacent
upper coil arms 534 in contact with metal brush 910 is shaped into a rough
spiral developing backwards in the rotating direction towards the outer
periphery thereof as illustrated in FIG. 8. By shaping clearance grooves
535 into a rough spiral in this way, metal brush 910 contacts the upper
coil arm 534 serially from the inside thereof where wind velocity is low,
to the outside thereof where wind velocity is high. As a result, metal
brush 910 has a sliding contact with upper coil arm 534 and can be
prevented from jumping on upper coil arm 534.
In addition, owing to clearance groove 535 provided between mutually
adjacent upper coil arms 534, when armature coil 530 rotates, centrifugal
wind produced by clearance grooves 535 between mutually adjacent upper
coil arms 534 flows from the inside to the outside. The centrifugal wind
produced by the rotation of clearance groove 535 between mutually adjacent
upper coil arms 534 in contact with metal brush 910 is used to cool the
heat generated by the sliding contact between metal brush 910 and upper
coil arms 534 and blow off the metal brush wear powder to the outside
radially (described later).
The pair of upper coil arms 534 have small projections 534c protruding
innards in the axial direction on the inner surfaces of upper coil arms
534, with projections 534c facing each other as illustrated in FIG. 4.
Projection 534c is disposed between upper coil arm 534 and lower coil arm
537 (described later) and fit into a hole (positioning part) 561 formed in
insulating spacer (insulator) 560, as shown in FIG. 9, that insulates
upper coil arm 534 from lower coil arm 537.
Lower coil bar 532 composing the lower armature coil is made of the same
highly conductive material (e.g., copper) as the upper coil bar 531, and
extends parallel to fixed magnetic pole 550. Lower coil bar 532 includes
lower coil trunk 536 held within slot 524 and a pair of lower coil arms
537 extending from both the respective ends of lower coil trunk 536
turning innards therefrom to be perpendicular to the axial direction of
shaft 510. Both ends of lower coil trunk 536 are inserted into recessed
parts 537a formed at one end of the respective pair of lower coil arms 537
and joined thereto.
Upper coil arms 534 are insulated from lower coil arms 537 by insulating
spacer 560. Lower coil arms 537 are insulated from armature core 520 by
insulating ring 590 made of resin (e.g., nylon or phenolic resin.)
Lower coil trunk 536 is a linear bar with rectangular cross section as
illustrated in FIGS. 4 through 7. The periphery of lower coil trunk 536 is
covered with lower insulating film 541 (e.g., nylon or paper). Lower coil
trunk 536 covered with lower insulating film 541 is firmly held within the
slot 524 together with upper coil trunk 533 covered with upper insulating
film 540 as illustrated in FIG. 7.
Of the pair of lower coil arms 537, one located at the side of gear 511 is
inclined in the reverse direction to the inclination direction of upper
coil arm 534. The other lower coil arm 537 located at the rear side is
also disposed so as to be inclined in the reverse direction to the
inclination direction of upper coil arm 534. The pair of lower coil arms
537 are inclined to the radial direction at the same angle to lower coil
trunk 536 and formed in the same shape. Accordingly, as is the case with
the upper coil bar 531, even if lower coil arms 537 are horizontally
turned 180.degree. around the center of lower coil bar 532, lower coil bar
532 takes the same shape as if lower coil arms 537 were not turned. That
is, as there is no difference in shape between the pair of lower coil arms
537, the assembly of lower coil bars 532 to armature coil 520 has a high
efficiency.
At the inner peripheral end parts of each of the pair of lower coil arms
537 are provided lower inner extension portions 539 extending in the axial
direction. The outer periphery of lower inner extension portion 539 is fit
in holes 561 formed in the outer peripheral portion of insulating spacer
560. The outer periphery of lower inner extension portion 539 is laid on
the inner periphery of upper inner extension portion (protruded portion)
538 formed at the end of upper coil arm 524 and electrically and
mechanically connected thereto by a joining technique, such as welding.
Here, the inner periphery of lower inner extension portion (protruded
portion) 539 is distantly disposed from shaft 510 for purpose of
insulation.
At the inner peripheral end parts of each of the pair of upper coil arms
534 are provided upper inner extension portions 538 extending in the axial
direction. The inner periphery of upper inner extension portion 538 is
laid on the outer periphery of above-described lower inner extension
portion 539 formed at the inner end of lower coil bar 532 and electrically
and mechanically connected thereto by a joining technique, such as
welding. The outer periphery of upper inner extension portion 538
contacts, through insulating cap 580, the inside of outer peripheral
annular part 571 of fixing member (collar) 570 press fit on shaft 510 and
fixed thereto as shown in FIGS. 10 and 11.
Insulating spacer 560 is a thin plate ring made of resin (e.g., epoxy
resin, phenolic resin, nylon). In the outer peripheral portion thereof are
provided a plurality of holes 561 in which projections 534c of upper coil
arms 534 are fit as illustrated in FIG. 9. On the inner peripheral portion
of insulating spacer 560 are provided recessed parts 562 in which lower
inner extension portion 539 formed on the inside of lower coil arms 537
are fit. Holes 561 and recessed parts 562 of insulating spacer 560 are
used to position and fix armature coil 530. The plurality of holes 561 in
which projections 534c of upper coil arms 534 are fit have been preformed
in the outer peripheral portion of insulating spacer 560. It is also
acceptable that upper coil arms 534 are stamped from the outer peripheral
side thereof to form the projections 534c on upper coil arms 534 and
simultaneously form holes 561 in insulating spacer 560 by using
projections 534c as stamps. According to this method, upper coil arms 534
are hardened due to plastic deformation, whereby the wear thereof that may
be caused by sliding contact with the metal brush 910 can be reduced.
Fixing member 570 is an iron annular material. As illustrated in FIG. 10,
fixing member 570 comprises inner peripheral annular part 572 to be press
fit on shaft 510, regulating ring. 573 extending in the axial direction
for preventing upper coil arms 534 and lower coil arms 537 from unfolding
in the axial direction, and outer peripheral annular part 571 covering
upper inner extension portions 538 of upper coil arms 534 for preventing
the internal diameter of armature coil 530 from enlarging due to
centrifugal force. Here, fixing member 570 has disc-like insulating cap
580 made of a resin (e.g., nylon), as illustrated in FIG. 11, between
upper coil arm 534 and lower coil arm 537 to insulate upper coil arm 534
from lower coil arm 537.
Fixing member 570 is disposed in front of the starter and contacts the rear
of front partition wall 800 disposed adjacent to the front of fixing
member 570 to serve also as a thrust pad for regulating the forward
displacement of armature 540. On the other hand, fixing member 570
disposed at the back of the starter contacts the front of end frame 900
disposed adjacent to the rear of fixing member 570 to also serve as a
thrust pad for regulating the backward displacement of armature 540.
Each fixing member 570 fixing the inside end part of armature 530 serves as
a thrust pad for armature 540 as described above. Thus, there is no need
to specially provide any thrust pad for armature 540. As a result, the
number of the parts and components required for a starter motor can be
reduced as well as allowing for reduction in the number of man-hours
needed for assembly.
As a means for positioning and fixing upper coil bars 531 and lower coil
bars 532 of armature coil 530 to armature core 520, slots 524 and fixing
claws 525 of armature core 520, holes 561 and recessed parts 562 of
insulating spacer 560, and fixing members 570 which are press fit on the
shaft 510 are utilized.
Slot 524 of armature core 520 houses upper coil trunk 533 and lower coil
trunk 536. By bending fixing claws 525 towards the inside diameter as
indicated by the arrows of FIG. 7, upper coil trunk 533 and lower coil
trunk 536 are so firmly fixed in each slot 524 that the displacement of
upper coil trunk 533 and lower coil trunk 536 towards the outer diameter
under a centrifugal force applied thereto can be prevented. Here, it
should be noted that as the outer periphery of upper coil trunk 533 is
insulated by two insulating films, i.e., lower insulating film 541 and
upper insulating film 540, sufficient insulation is ensured even when
fixing claws 525 are bent towards the inside diameter so as to encroach
thereon.
Recessed parts 562 formed on the inner periphery of insulating spacer 560
in which lower inner extension portions 539 of lower coil arms 537 are fit
position lower coil arms 537. Recessed parts 562 also prevent the
displacement of lower coil arms 537 towards the outside diameter under a
centrifugal force applied to lower coil arms 537.
Holes 561 made in the outer periphery of insulating spacer 560 in which
projections 534a of upper coil arms 534 are fit position the upper coil
arms 534. Holes 561 also prevent the displacement of upper coil arms 534
towards the outside diameter under a centrifugal force applied to upper
coil arms 534.
Fixing members 570 hold upper inner extension portion 538 and lower inner
extension portion 539 joined to each other to prevent the displacement of
the inside diameter portion of armature coil 530 towards the outside
diameter under a centrifugal force applied thereto. Furthermore, fixing
members 570 regulate the displacement of the axial end part of upper inner
extension portion 538 and lower inner extension portion 539 joined to each
other to prevent the elongation of the axial length of armature coil 530.
In order to prevent the elongation of the axial length of upper coil arms
534 and lower coil arms 537 when the electric rotating machine as the
starter motor is in operation, it is necessary to secure a space within
the starter to accommodate such elongation. In this embodiment, however,
as fixing members 570 prevent the elongation of the axial length of upper
coil arms 534 and lower coil arms 537, the starter requires no such spare
space, whereby the axial length of the starter can be shortened.
The procedure for assembling the armature will now be described in detail.
First, armature core 520 stacked with core plates 521 is press fit around
shaft 510. Second, insulating rings 590 are disposed at both sides of
armature core 520. Third, lower coil trunks 536 of lower coil bar 532 are
housed within respective slots 524 together with lower insulating film
541.
Fourth, insulating spacers 560 are attached to both sides of lower coil
arms 537 of lower coil bars 532, and lower inner extension portions 539
are disposed within recessed parts 562, whereby the positioning of lower
coil bars 532 is completed.
Fifth, upper coil trunks 533 of upper coil bar 531 are housed within
respective slots 524 together with upper insulating film 540. In this
process, projections 534c of upper coil arms 534 are fit in holes 561 of
insulating spacers 560, whereby the positioning of upper coil bars 531 is
completed.
Sixth, upper inner extension portion 538 of upper armature coil trunk 533
and lower inner extension portion 539 of lower armature coil trunk 536 are
joined to each other by a joining technique, such as welding, to ensure an
electrical and a mechanical connection.
Seventh, each fixing claw 525 of armature coils 520 is bent towards the
inner periphery to fix upper coil trunk 533 and lower coil trunk 536
within each slot 524. Then, fixing members 570 are press fit on shaft 510
from both sides to cover the outer periphery of upper inner extension
portions 538 of armature coils 530, whereby the displacement of upper coil
arms 534 in the axial direction towards the outer periphery can be
prevented.
By using the above procedure, the assembly of the armature is completed.
In this embodiment, permanent magnets fixed on yoke 501 with sleeves
contacted to the inner periphery thereof are used as fixed magnetic poles
550. It is also acceptable that a field coil electrically generating a
magnetic force may be used instead of the permanent magnets as fixed
magnetic poles 550.
At an end part of yoke 501 of electric rotating machine 500 is fixed end
frame 900. On end frame 900, metal brush holder 920 is provided. On the
inside of the metal brush holder 920 is provided metal brush 910 slidably
movable in the axial direction. Metal brush 910 is pressed against upper
coil arms 534 of armature coils 530 by spring 930 housed within metal
brush holder 920.
FIG. 12 typically illustrates the winding of the armature coil 530.
Illustrated in this Figure is the case where metal brush 510 is disposed
on upper coil arms 534.
In the electric rotating machine according to the present invention, upper
coil arms 534 of upper armature coil bars 531 and lower coil arms 537 of
lower armature coil bars 532 are disposed so as to be roughly parallel to
each other on the axial end faces of armature core 520 only through the
insulating rings 590 and the insulating spacers 560 with metal brush 910
being disposed on upper coil arms 534. In this arrangement, the overall
length of the armature can significantly be shortened. Also in this
arrangement, as a commutator, which has conventionally been required
separately from armature coil, can be dispensed with, thus allowing the
manufacturing procedure for the armature to be shortened and simplified.
Furthermore, as projections 534c of upper coil arms 534 are fit in holes
561 of insulating spacer 560, the displacement of upper coil arms 534
towards the outer periphery is regulated, and the amount of the
protrusions of upper coil arms 534 from the end faces of armature core 520
is small. In addition, as extension portions 538 of upper coil trunks 532
and extension portions 539 of lower coil trunks 533 are strongly pressed
against and fixed to the axial side of armature core 520 by fixing members
570, the resistance to centrifugal force can be remarkably increased.
Moreover, as extension portions 539 of lower coil arms 537 are fit in
recessed parts 562 of insulating spacer 560, the displacement of lower
coil arms 537 in the radial direction towards the outer periphery can be
prevented. As a result, the armature of this embodiment can withstand more
than two times as high a rotation speed as can conventional structures.
Furthermore, the heat generated at upper coil arms 534 with which metal
brush 910 contacts is also transmitted relatively easily to armature core
520 through insulating spacers 560, lower coil arms 537 and insulating
rings 590, and then discharged. In this arrangement, the rise in the
temperature of metal brush 910 and this contact face thereof can also be
reduced. This rise in the temperature can further be reduced by using high
heat-conduction ceramic or the alternative for insulating spacers 560 and
insulating caps 580.
In addition to the above, according to the present invention as illustrated
in FIG. 8, upper coil arms 534 are arranged spirally and between mutually
adjacent upper coil arms 534 are formed clearance grooves 535, roughly
corresponding to the thickness of the coil arms, which ranges from about
1.5 mm to about 3.5mm. Clearance grooves 535 at the side of upper coil
arms 534 with which metal brush 910 contacts are shaped protruding against
the rotational direction of armature core 520, whereby clearance grooves
535 function as centrifugal fans by the rotation of the armature. That is,
airflow is generated from the inner periphery of upper coil arms 534 to
the outer periphery thereof. This airflow has a velocity of approximately
4 m/s at or around the outer periphery of upper coil arms 534 when the
armature rotates at 8,000 rpm, exerting a cooling effect on upper coil
arms 534 and metal brush 910.
Furthermore, by lap winding armature coil 530, clearance grooves 535 at the
side not contacting the metal brush 910, i.e. on the side of reduction
gear 511, are also shaped so as to protrude against the rotational
direction of armature core 520. As a result, clearance grooves 535 can
also function as centrifugal fans, whereby upper coil arms 534 at this
side can also be cooled in the same way.
Moreover, by making a through hole in a part of yoke 501 of motor 500,
electrical current leaks between the coils, due to powder worn off metal
brush 910 caused when motor 500 is downsized, can be prevented by the
above-described function as centrifugal fans. That is, the powder is
completely discharged to the outside from the through hole of yoke 501.
As clearance grooves 535 are inevitably formed by inserting the armature
coils 530 into slots 524 of armature core 520, there is no need to form
clearance grooves 535 by machining or any other means, whereby the
manufacturing cost can be remarkably reduced. In addition, as the
thickness of clearance groove 535 can be set to the thickness of upper
coil arm 534, clearance grooves 535 can be used sufficiently longer, even
if the sliding surface of metal brush 910 is worn.
Furthermore, by using a metal for metal brush holder 920, the heat
generated on metal brush 910 can be dissipated through metal brush holder
920.
FIGS. 13 through 17 illustrate other embodiments of the method for
producing the armature coil, particularly the method for producing coil
trunks 533 and 536 and coil arms 534 and 537 separately.
In FIGS. 13 and 14, upper coil arms 534 and lower coil arms 537 are joined
to both ends of upper coil trunk 533 and lower coil trunk 536,
respectively. Particularly in the embodiment illustrated in FIG. 14, in
one end part of upper coil arm 534 and lower coil arm 537 are provided
through holes 534d and 537d, respectively. In through holes 534d and 537d
are fit small diameter portions 533a and 536a, respectively, of both ends
of upper coil trunk 533 and lower coil trunk 536 and joined thereto
respectively. It is also acceptable that small diameter portions 533a and
536a are shaped like square pillars. By fitting small diameter portions
534a and 537a in through holes 534d and 537d, the joining accuracy and the
mechanical strength can be improved, and consequently the reliability can
be improved.
In the embodiment illustrated in FIG. 15, one end part of upper coil trunk
533 and lower coil trunk 536 are formed in one piece through connecting
parts 533b and 536b, and to the other end part of upper coil trunk 533 and
lower coil trunk 536 are joined one end part of upper coil arm 534 and
lower coil arm 537, respectively.
In the above arrangement, as upper coil trunk 533 and lower coil trunk 536
can be produced separately from upper coil arm 534 and lower coil arm 537,
the yield of the material of each component can be improved and mass
production can be improved. Moreover, in producing the armature, it is
also acceptable that linear coil trunks 533 and 536 are inserted into
slots 524 of armature core 520 in advance and then one end part of upper
coil arm 534 and lower coil arm 537 are joined to linear coil trunks 533
and 534. In this case, an armature core of semi-closed slot type or closed
slot type can be used, whereby there is no need to provide fixed claws 525
to close the openings of slots 524 after coil trunks 533 and 536 have been
inserted.
Next, description is provided of embodiments in which upper coil trunk 533
and lower coil trunk 536 are produced integrally with upper coil arm 534
and lower coil arm 537, respectively, with reference to FIGS. 16 and 17.
Both embodiments adopt a production method by means of press machining
which is advantageous in terms of production cost.
In the embodiment illustrated in FIGS. 16A through 16C, first, bar-like
shaped upper coil trunk 533 and lower coil trunk 536, trapezoidal-shaped
upper coil arm 534 and lower coil arm 537, and upper inner extension
portion 538 and lower inner extension portion 539 are integrally stamped
out of a plate material as illustrated in FIG. 16A. Here, the thickness is
uniform throughout the stamped portions. Second, as illustrated in FIG.
16B, upper coil arm 534 and lower coil arm 537 are bent to the specified
angle at the boundary portions between upper and lower coil trunks 533 and
536 and trapezoidal upper and lower coil arms 534 and 537, respectively.
In this case, two cuts 533c and 536c are provided with the distance
thereof approximating the width of coil trunks 533 and 536. Third, as
illustrated in Fig. 16C, coil arms 534 and 537 are bent at roughly right
angles to coil trunks 533 and 536, and then upper inner extension portion
538 and lower inner extension portion 539 are bent so as to be parallel to
the coil trunks 533 and 536. In this arrangement, shoulders 534e and 537e
of coil arms 534 and 537 respectively are roughly at the same level as top
surfaces 533d and 536b of coil trunks 533 and 536, respectively.
Accordingly, coil arms 534 and 537 up to the vicinity of top surfaces 533d
and 536d of the coil trunks can be used as the contact face for metal
brush 910, whereby the commutator area can widely and effectively be
obtained, and the current density of the commutator surface can be
reduced.
In the embodiment illustrated in FIGS. 17A through 17D, first, wire
material 100 made of a good conductor, such as copper, is cut to the
specified length as shown in FIG. 17A. Second, as illustrated in FIG. 17B,
the portions corresponding to coil arms 534 and 537 are bent to the
specified angles in the longitudinal direction. Third, as illustrated in
FIG. 17C, coil arms 534 and 537 are shaped into a wide trapezoid and upper
inner extension portion 538 and lower inner extension portion 539 are
shaped into narrow protrusions, respectively. Coil arms 534 and 537 are
pressed to spread the side portions in the width direction to be wider
near coil trunks 533 and 536 and narrower near the extension portions.
Extension portions 538 and 539 are drawn in the longitudinal direction to
be narrow. Last, as illustrated in FIG. 17D, coil arms 534 and 537 are
bent at right angles to coil trunks 533 and 536 respectively, and
extension portions 538 and 539 are also bent at right angles to coil arms
534 and 537 respectively. This completes the whole procedure. Here, as
coil arms 534 and 537 are formed to be thinner towards coil trunks 533 and
536, the stress caused by bending does not reach there, whereby the
commutator face can be as widely and effectively obtained as the
embodiment illustrated in FIG. 16. In addition, as coil arms 534 and 537
are formed by press machining to be wide, coil arms 534 and 537 are hard
enough to be used as they are as contact faces for metal brush 910.
Further, there is no need to widen the portions of upper coil arms 534 and
lower coil arms 537 that do not contact metal brush 910 as illustrated in
FIG. 17D. Also, it is advisable that upper coil trunk 533 and upper coil
arm 534 be made of a good conductor with Vickers hardness of 55 or more.
The Vickers hardness of copper that is normally 50 can be raised to be 55
or more by press machining.
Furthermore, as illustrated in FIG. 18, by using the shear droop side
(i.e., side with no flash) made by press machining as the face of upper
coil arm 534 to be contacted by metal brush 910, the edge portions of
upper coil arm 534 are rounded, whereby the slidability of metal brush 910
is improved.
FIGS. 19 through 21 illustrate other embodiments of the connection between
upper coil arm 534 and lower coil arm 537.
In FIG. 19, upper inner extension portion 538 is not formed at one end of
upper coil arm 534, and lower inner extension portion 539 of lower coil
arm 537 is extended at most to the surface of upper coil arm 534.
Accordingly, upper inner extension portion 538 of upper coil arm 534 can
be eliminated, whereby the processing cost of upper coil bar 531 can be
reduced.
As illustrated in FIG. 20, it is also acceptable that lower inner extension
portion 539 of lower coil arm 537 be shorter than that of the type
illustrated in FIG. 19 and connected to a part of the end face of upper
coil arm 534. As an effect of this arrangement, lower inner extension
portion 539 can easily be joined to upper coil arm 534.
As illustrated in FIG. 21, it is also acceptable that short inner extension
portions 538 and 539 extend from upper coil arm 534 and lower coil arm
537, respectively, and join to each other. In this arrangement, as the
extension portions 538 and 539 can be short, the processing thereof can be
easy.
By using a liquid resin or a thin adhesive sheet for insulating spacer 560
and insulating ring 590, the small clearances between upper coil arm 534
and lower coil arm 537 and between lower coil arm 537 and armature core
520 can be eliminated. As a result, the heat conductivity can further be
improved, and the micromotion of the coil arms 534 and 537 can be
prevented.
Furthermore, by applying an insulating coating to upper and lower coil
trunks 533 and 536 and coil arms 534 and 537, upper and lower insulating
films 540 and 541 can be eliminated. As a result, parts otherwise
required, such as insulating spacer 560, are not needed.
The second embodiment of the present invention is depicted in FIG. 22. In
the second embodiment, open slots are adopted as slots 524 of armature
core 520. After armature coils 530 are fit in slots 524, thin non-magnetic
cylinder 600 is mounted on the outer periphery of armature core 520 to
prevent the projection of armature coils 530 in the radial direction. In
this arrangement, the outer periphery of armature core 520 is so smooth
that the windage loss during the rotation of the armature can be reduced
and the wind noise can be reduced, resulting in a low-noise operation.
Accordingly, this embodiment is suitable for use as a high speed electric
rotating machine.
The third embodiment of the present invention is depicted in FIG. 23. In
the third embodiment, both axial end sides of the upper coil trunk 533,
i.e., the outer peripheral portions axially apart from armature core 520,
are blocked by thin non-magnetic cylinders 610. In this arrangement,
fixing members 570 as used in the first embodiment are unnecessary.
Accordingly, a larger area towards the inner periphery can be used as the
sliding surface for metal brush 910, and metal brush 910 can have a larger
cross sectional area. As a result, the electric rotating machine can have
a higher output and a longer service life.
The fourth embodiment of the present invention is shown in FIG. 24. In the
fourth embodiment, all the components including armature core 520 and
upper coil trunk 533 are integrally molded with molded resin 602.
In the fifth embodiment illustrated in FIG. 25, upper coil trunk 533
extends in the axial direction by the thickness of metal brush 910 to
slidably hold metal brush 910 on the outer periphery of the end part of
upper coil trunk 533. A leaf spring is used as metal brush spring 930. In
extending upper coil trunk 533 in the axial direction, insulating spacer
560 having a large thickness is used.
In addition, by forming spaces 551 between fixed magnets 550 and disposing
metal brush 910 in spaces 551, the space for housing metal brush 910 can
be secured, and at the same time, the overall axial length of the electric
rotating machine can further be shortened.
In the sixth embodiment illustrated in FIG. 26, metal brush 910 at one side
is disposed on the outer periphery of the end part of upper coil trunks
533 as in the fifth embodiment, and metal brush 910 at the other side is
disposed so as to slide on the inner periphery of lower inner extension
portion 539 of lower coil arm 537. Metal brushes 910 at both sides are
forced against coil trunk 533 and extension portion 539, respectively, by
the spring forces of the leaf springs 930. In this arrangement, the inner
peripheral space of lower inner extension portion 539 of lower coil arm
537 is utilized for housing metal brush 910 on the other side, whereby the
overall axial length of the electric rotating machine can further be
shortened.
In the sixth embodiment, it is also acceptable that upper coil arm 534 be
provided with an extension portion protruding towards lower coil arm 537
instead of lower extension portion 539 of lower coil arm 537, with metal
brush 910 sliding on the extension portion from upper coil arm 534 rather
than on lower extension portion 539.
It is to be noted that, in the first six embodiments, the description of
upper coil arm 534 and lower coil arm 537 being roughly parallel to the
end face of armature core 520 means that the angle formed between the
upper and lower coil arms 534 and 537 and the end face of armature core
520 is 45 degrees at most.
In addition, in the embodiments of the electric rotating machine according
to the present invention, two coil trucks are housed within the slot 524.
It is also acceptable that any even number of coils, such as four coils,
are used.
FIG. 27 shows the axial cross-sectional view of the electric rotary machine
according to the seventh embodiment of this invention. FIG. 28A and 28B
are enlarged cross sections in the axial direction of the commutator
portion.
In the approximate center of rotary shaft 10, the armature core 11 formed
by layering multiple disc-shaped steel plates 15 is fit. Multiple slots 13
extending axially are formed on the circumference of the armature core 11,
and armature coils 20e and 21e, also called conductors, are fit in the
upper and lower layers. Numeral 20e is a trunk of the outer or upper
conductor 20, and 21e is a trunk of the inner or lower conductor 21.
The commutator portion 40, which is made up by the outer conductor 20, is
formed on the axial rear (right) end of armature core 11. On the front
(left) end, the non-commutator portion 90, described later, is formed,
thus configuring the armature (rotor) of the electric rotating machine.
Both axial ends of rotary shaft 10 are supported by bearing 61 installed
on end frame 60 of the electric rotating machine and bearing 62 installed
on the members not shown in the drawing. End frame 60 blocks the opening
of the yoke 70 made of cylindrical steel plates. In the inner
circumference of the yoke 70, four magnetic cores 51 onto which field
coils 50 are wound are fixed near the periphery of the armature core 11.
Each of these coils is fixed so that they are separated 90 in the
circumferential direction. The yokes 70, field coils 50 and magnetic cores
51 constitute a stator. Gears 12 are installed on rotary shaft 10. These
gears are engaged with the gears of a reduction gear mechanism (such as
the epicycle reduction gear mechanism) not shown in the figure. The
rotation of rotary shaft 10 is conveyed to the gears not shown in the
figure.
Brush holder 80 is fixed onto end frame 60, and brush 81 is held inside so
that it can freely slide in the axial direction. Brush 81 is pressed
against first armature coil holding portion or upper arm 20b of commutator
portion 40, described later, by spring 82 in brush holder 80.
Commutator portion 40, non-commutator portion 90, armature coil 20e and
armature coil 21e are explained in detail hereinunder.
Third armature coil holding portion or lower arm 21b is arranged on the
right side end of armature core 11 with insulation material 21a. First
armature coil holding portion 20b is arranged on the surface with
insulation material 20a. Fourth armature coil holding portion or lower arm
21d is arranged on the right side end of armature core 11 with insulation
material 21c. Second armature coil holding portion or upper arm 20d is
arranged on the surface with insulation material 20c. Insulation material
21a, third armature coil holding portion 21b, insulation material 20a and
first armature coil holding portion 20b constitute commutator portion
(brush side) 40. Insulation material 21c, fourth armature coil holding
portion 21d, insulation material 20c and second armature coil holding
portion 20d constitute noncommutator portion (opposing brush side) 90.
Conductor 20e, first armature coil holding portion 20b and second armature
coil holding portion 20d are made of copper, etc., and are integrally
formed with cold casting, etc., to create outer conductor 20. Furthermore,
conductor 21e, third armature coil holding portion 21b, and fourth
armature coil holding portion 21d are made of copper, etc., and are
integrally formed with cold casting, etc., to create inner conductor 21.
The arrangement of armature coil holding portions 20b and 21b on the
commutator side is shown in FIGS. 28a and 28B.
Insulation materials 20a and 21a are sandwiched between armature coil
holding portions 20b and 21b and between armature coil holding portion 21b
and armature core 11. Insulation materials 20a and 21a have holding plate
separator wall portions 20r, 20s and 21r that protrude to commutator plate
(armature coil holding portion) 20b that neighbors circumferentially, the
curvy long-slot clearance or groove 20f between tow holding portions 20b,
and to the holding plate (armature coil holding portion) 21b, and the
curvy long-slot clearance 21f. The protrusion amount of the holding plate
separator wall portion 20r is less than the shaft-wise direction thickness
of the armature coil holding portion 20b. When the space or groove 20f is
seen from the armature radial direction (refer to FIG. 28A), space 20t is
formed at the end of the holding plate separator wall portion 20r, and
that the space 20t is an undercut of the commutator.
Armature coil holding portions 20d and 21d and insulation materials 20c and
21c on the non-commutator side have the same type of form and arrangement
as the armature coil holding portion 20b and 21b and insulation materials
20a and 21a on the commutator side. The space on the non-commutator
portion that corresponds to space 20t acts as the fan that generates the
centrifugal wind during rotation of the armature.
Furthermore, as shown in FIGS. 27 and 30, protrusions 20g, 21g, 20h and 21h
that protrude in the direction opposite from armature core 11 are set on
the inside diameter ends of the armature coil holding portions 20b, 21b,
20d and 21d. In other words, protrusion 20g protrudes in the axial
direction from holding portion 20b, protrusion 21g from holding portion
21b, protrusion 20h from holding portion 20d, and protrusion 21h from
holding portion 21d. The collar 30 fixed on the rotary shaft 10 directly
contacts the circumference of protrusion portion 20g via insulation
material 32. In the same manner, collar 31 fixed on rotary shaft 10
directly contacts the outer circumference of protrusion portion 20h via
the insulation material 33.
Next, method of assembling the armature coil in this embodiment is
explained.
Insulation film or insulation material sheet is sprayed, baked, wound, or
stuck with adhesive onto the surface of conductor 20e beforehand.
Insulation film or insulation material sheet is also applied on the
surface of conductor 21e in the same method as for conductor 20e.
First conductor 21e and then conductor 20e are inserted into slot 13 of
armature core 11. At this time, armature core's right side plain washer
type insulation material 20a, armature coil holding portion 20b,
insulation material 21a and .armature coil holding portion 21e are
arranged as explained above. When both conductors 20e and 21e have been
inserted into all slots 13, both protrusion portions 20g and 21g are
connected by welding, etc., and then both protrusion portions 20h and 21h
are connected by welding, etc.
After connecting, pressure to press-in and compress the outer armature coil
holding portions 20b and 20d towards the axial direction of each armature
is applied. The insulation materials 20a, 20c, 21a and 21c are deformed.
The protruding portions, the holding plate separator wall portions 20r,
20s and 21 shown in FIG. 28, are formed into the narrow clearances created
when the insulation materials 20a, 20c, 21a and 21c neighbor
circumferentially toward the commutator side and non-commutator side. If
the insulation materials 21a and 21c are formed to protrude into slot 13
of part of the armature core 11 at this time, the conductor and core
insulation will be further rigid.
Thus, electrical insulation resin material that deforms under adequate
compression pressure is most suitable for the insulation materials 21a and
21c.
At the same time, collars 30 and 31 and insulation materials 32 and 33 are
fit from the left and right onto the rotary shaft 10 shown in FIG. 27.
Collar 30 and protrusions 20g and 21g are assembled to directly contact
via insulation material 32, and collar 31 and protrusions 20h and 21h are
assembled to directly contact via insulation material 33. Collars 30 and
31 deform in plasticity due to this fitting force, and resin 30d protrudes
to the ring groove 10a to restrict displacement of collars 30 and 31.
If collars 31 and 32 are pressed and compressed toward the armature core
axial side after assembly, holding portions 20b, 21b, 20d and 21d of both
conductors 20 and 21 will be rigidly pressed against the core 11, and
insulation materials 20a, 21a, 20c and 21c will also be rigidly fixed.
With the pressing and compressing of the collars 30 and 31, the protrusion
30d and 31d corresponding to the ring grooves 10a and 10b on the
circumference of rotary axis will be rigidly fixed to the inside diameter
of collars 31 and 33, and the fixing of the raised and formed collars 30
and 31 to the rotary shaft 10 will also be rigid. If the end of the inner
cylinder of collars 30 and 31 are directly contacted against core 11, the
core 11 can be fixed onto the rotary shaft via collars 30 and 31.
The circumference of the axial protrusions 20g and 20h of the outer
conductor 20 fits with each collar 30 and 31 as explained above when
collars 30 and 31 have been assembled so the rising of the conductors 20
and 21 in the radial direction due to centrifugal force during rotation of
the armature can be prevented.
An electrical connection diagram for an embodiment of the armature coils
(conductors) 20e and 21e and the armature coil holding portions 20b, 21b,
20d and 21d in this invention is shown in FIG. 29.
As is clear with the above explanation, with this embodiment, it is assumed
that the coil ends of the armature coil are converted into the third
armature coil holding portion 21b of the inner conductor 21, so the axial
length of the armature can be reduced, and the motor size and weight can
be reduced. Furthermore, as the centrifugal force is applied in the
parallel direction onto the contact boundary surface of the resin
insulation materials 21a and 20a, third armature coil holding portion 21b
and first armature coil holding portion 20b, the anti-centrifugal force
properties of the commutator portion 40 can be improved. Furthermore, an
increase in the sliding surface area with the brush 81 has been realized.
The resistance heat and frictional heat generated at the first armature
coil holding portion 20d are favorably cooled by the centrifugal wind flow
thus generated. The heat is also absorbed by the large heat capacity
armature core 11 with solid heat transfer, allowing this structure to be
applied to motors for fully-closed starter/motors. The effect is
especially remarkable for reducing the size and increasing the rotation
speed with the incorporation of the reduction gear mechanism.
In addition, according to this embodiment, all parts excluding the rotary
shaft 10 can be produced with high productivity pressing and cold casting.
The only machining required for the entire armature is pressing and
welding. This is an area that conventionally required a large amount of
machining time. Cutting required conventionally for forming the undercut
between the commutator parts has been eliminated in this embodiment, as
the undercut portion is formed when the armature coil 20 is assembled to
armature core 11. Bothersome conventional commutator mold formation is
substituted for in this embodiment as the armature coil holding portions
20b and 20d are pressed in toward the armature core 11, and the insulation
materials 20a and 20c arranged in the inner side of holding portions 20b
and 20d are partially raised into the narrow clearances 20f between the
armature coil holding portions 20b that neighbor circumferentially, and
into the narrow clearances between armature coil holding portions 20d that
neighbor circumferentially.
With the conventional armature, the armature coil had to be fit into the
armature core slots, requiring processes such as impregnating the slots
with resin. However, with this embodiment, the armature coil can be
rigidly fit to the armature core with a very simple process by fitting the
protrusion portions 20g, 21g, 20h and 21h on the armature coils 20 and 21
with the collars 30 and 31. Thus, the conventional resin impregnation can
be omitted.
The insulation materials 20a, 21a, 20c and 21c are formed with an
insulation matter having an adequate plasticity such as paper or resin
sheets, etc. Insulation matter such as solid epoxy resin is used for the
insulation materials 20a, 21a, 20c and 21c. After assembling the conductor
and forming the protrusion portions 20r, 20s and 21r, etc., the material
can be hardened by heating, etc. Furthermore, after the conductor is
assembled, the expansion portions 20r, 20s and 21r of the insulation
materials 20a, 21a, 20c and 21c are formed by pressing in the armature
coil holding portions 20b, 2lb, 20d and 21d in the above embodiment.
However, the expansion portions 20r, 20s and 21r can be each formed for
insulation materials 20a, 21a, 20c and 21c beforehand. In this case, resin
material with an outstanding insulation property and strength such as
phenol resin can be used for the insulation materials 20a, 21a, 20c and
21c.
In the eighth embodiment, the other connection structure of the protrusion
portions 20g and 21g of the first armature coil holding portion 20b and
third armature coil holding portion 21b is modified from the seventh
embodiment.
FIGS. 31A through 31C show the state before the protrusion portions 20g and
21g of the first armature coil holding portion 20b and third armature coil
holding portion 21b are connected.
The circumferentially widened portion 20k is formed on the axial end of
protrusion portion 20g. The circumferentially widened portion 21k is also
formed on the axial end of protrusion portion 21g.
In this embodiment, armature coil 20e integrated with the first armature
coil holding portion 20b of slot 13 on the armature core 11 is inserted
into the outside diameter portion of the first armature coil holding
portion 20b and positioned circumferentially. At the inside diameter
portion, the circumferentially widened portions 20k of the axial end of
protrusion portion 20g integrated with armature coil holding portion 20b
are positioned circumferentially so that they are mutually neighboring and
contacting circumferentially. As a result, each first armature coil
holding portion 20b is arranged uniformly in the circumferential
direction.
Furthermore, the armature coil 21e integrated with the third armature coil
holding portion 21b of slot 13 on the armature core 11 is inserted into
the outside diameter portion of the third armature coil holding portion
21b and positioned circumferentially. At the inside diameter portion, the
circumferentially widened portions 21k of the axial end of protrusion
portion 21g integrated with armature coil holding portion 21b are
positioned circumferentially so that they are mutually neighboring and
contacting circumferentially. As a result, each third armature coil
holding portion 21b is arranged uniformly in the circumferential
direction.
The widths of the protrusion portion 20g axial end circumferentially
widened portion 20k and the protrusion portion 21g axial end
circumferentially widened portion 21k is arranged so that the
circumferential width center is approximately aligned.
The arrangement state before the protrusion portions 20h and 21b in the
second armature coil holding portion 20d and fourth armature coil holding
portion 21d is the same as that explained above.
FIG. 32 shows the state with the protrusions 20g and 21g of the first
armature coil holding portion 20b and third armature coil holding portion
21b welded.
When the circumferentially widened portions 20k and 21k that are the axial
ends of protrusion portions 20g and 21g are melted with TIG welding, etc.,
the melted end changes into a near-spherical shape due to its own surface
tension. The radial dimensions increase and the width dimensions in the
circumferential direction decrease. In other words, the shape changes from
the original circumferentially widened portions 20k and 21k in which the
circumferential direction was wider than the radial direction into a
spherical shape. The shape hardens to create the spherical contact portion
L.
Thus, since the circumferentially widened portions 20k and 21k of the
protrusion 20g and 21g have been shaped into the spherical contact portion
L, the circumferential width of the circumferentially widened portions 20k
and 21k have decreased. Thus, the circumferential clearance x is
accurately created between each protrusion portion 20g and 21g that
neighbor circumferentially.
In other words, while the first armature coil holding portion 20b and third
armature coil holding portion 21b contact, a clearance is accurately
created circumferentially between the neighboring first armature coil
holding portions 21b and neighboring third armature coil holding portions
21b.
On the end of the armature core 11 that is opposite from that above, a
spherical contact portion is formed with welding for melting the
circumference winding portion of protrusions 20h and 21h as with the third
armature coil holding portion, and thus the same effect can be achieved.
The narrow clearances 20f formed between the first armature coil holding
portions 20b that neighbor circumferentially due to the above connections
become the undercut for the commutator.
In this embodiment, the protrusion portions 20g and 21g gradually widen
circumferentially toward the axial opposing armature core as shown in FIG.
31C. Only each end on the axial opposing armature core contact each other.
In other words, the circumference widened portions 20k and 21k are formed
almost only at the end of the protrusion portions 20g and 21g. Thus, when
this portion is heated and melted, the protrusion portions 20g and 21g
including each circumferentially widened portion 20k and 21k each become
independent spherical contact portions, and the protrusion portions 20g
and 21g that neighbor circumferentially are not integrally welded. Every
other protrusion portion 20g and 21g in the circumferential direction can
be welded at once, and then the remaining protrusion portions 20g and 21g
can be welded at once.
Next, the collars 30 and 31 will be explained with reference to FIG. 33.
The collar 30 fixed onto the rotary shaft 10 directly contacts the
spherical contact portion L of the protrusion portion 20g via insulation
material 32. In the same manner, the collar 31 fixed to the rotary shaft
10 directly contacts the outer circumference of the protrusion portion 20h
via the insulation material 33.
Collar 30 is a commutator fixing material made of soft metal such as
aluminum. As shown in FIG. 33, the collar 30 is configured of the inner
cylinder portion 30a fit onto the rotary shaft 10, the ring plate portion
30b that extends toward the outer radial direction from the base end
portion of the inner cylinder portion 30a, and the outer cylinder portion
30c that extends from the ring plate portion 30b outside diameter end to
the armature core 11. The expansion portion 30d that fits into the ring
groove 10a on the rotary shaft 10 is formed on the inside diameter end of
the ring plate portion 30b. Collar 31 has the same structure as collar 30.
In this eighth embodiment, outer conductor 20 and inner conductor 21 are
engaged with the collar fit on the spherical contact portion, by that
improving the anti-centrifugal force properties of the outer conductor 20
and inner conductor 21.
In addition, with conventional armatures, copper wires had to be wound into
a designated shape, the coil ends had to be twisted, and the coil had to
be connected to a designated position in the commutator while curving the
coil. Instead of this complicated commutator coil that required accuracy,
a simple work process in which the outer conductor 20 and inner conductor
21 have been integrally formed, and these are inserted into slots from the
outside diameter side of the armature core 11 has been incorporated. In
this insertion process, the armature coils 20e and 21e are automatically
positioned circumferentially at the outside diameter portion of the
conductors 20 and 21. At the inside diameter portion of the conductors 20
and 21, when the protrusion portions 20g, 20h, 21g and 21b are assembled
to the neighboring phases, they are automatically positioned
circumferentially when directly contacted. The direct contact of each
circumferentially widened portion 20k and 21k of these protrusions 20g,
20h, 21g and 21h allows the circumferential width to be reduced and the
circumferential clearance to be automatically formed when welded.
The conductors 20 and 21 are fixed in the diameter and axial directions by
collars 30 and 31, so the armature coil does not need to be fixed to the
armature core as with the conventional armature. Thus, the armature coil
fixing process in which resin is impregnated into slots 13 is not longer
required. However, this process can be added.
In addition to TIG welding, arc welding or laser beam welding can be used.
The spherical contact portion L or protrusion portions 20g, 21g, 20h and
21h can be deformed with an external force before or after welding each
armature coil holding portions 20b, 21b, 20d and 21d. If the strength and
insulation properties of the armature coil insulation film are sufficient,
part or all of the insulation materials 20a, 21a, 20c and 21c can be
eliminated.
This invention has been described in connection with what are presently
considered to be the most practical and preferred embodiments of the
present invention. However, this invention is not meant to be limited to
the disclosed embodiments, but rather is intended to cover various
modifications and alternative arrangements included within the spirit and
scope of the appended claims.
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